Chronic Cough

Chronic cough can cause embarrassment and social isolation. Unfortunately over-the-counter and even prescription cough remedies usually do not work well. We understand the urgency to get to the root cause of the problem and our systematic approach is both time and cost efficient. As allergists with an interest in conditions of the upper airway, we believe we are uniquely positioned to help the chronic cough patient.

What is a cough?
A cough is a reflex of the airways. It may be triggered by nerves called cough receptors that are located throughout the respiratory tract. Inflammation (allergic or infectious) or irritation (acid or fumes) trigger a signal which is sent to the brain which then signals the lungs and breathing muscles to forcefully expel air.

What causes coughing?
Any cough receptor in the upper or lower airway from the nose, past the larynx and down to the lungs may initiate the cough reflex. The list of illnesses that may cause coughing is exhaustive but fortunately cough is usually due to one of a few ailments that are easily treated including the viral infections, allergies, asthma, acid reflux, bronchitis and sinusitis.

What tests are done to evaluate cough?
Since allergy, asthma, sinusitis and reflux cause the vast majority of chronic cough in otherwise healthy nonsmokers, testing is first directed towards diagnosing these conditions. Allergy testing, lung function testing and video endoscopy of the upper airway are simple and cost-effective examinations that may be done at the initial visit to the office. The video endoscopy is a key element of the workup of the irritable or “Hypersensitive Larynx“, an uncommon cause of chronic cough.

How is cough treated?
Over the counter cough remedies are supposed to suppress the cough reflex but are usually not effective. The best approach is to identify and treat the root cause of the cough:

Asthma-should improve with a short-acting bronchodilator. Inhaled controller asthma medications are so good these days that only severe asthmatics do not respond to them. If cough is the prinicpal manifestation of “asthma” and only responds to high doses of oral steroids, consider another cause such as reflux.

Acid reflux-should respond to strong acid suppressor therapy (proton pump inhibitors) but sometimes twice daily dosing is required. Some chronic cough patients with reflux respond temporarily to high doses of oral steroids (prednisone) leading doctor and patient to think it is asthma.

Postnasal drip-we consider this a confusing term. It refers to an irritation in the back of the throat but it could be due to reflux, allergy or sinus infection.

When should I worry about my cough?
Warning signs that a cough may be serious include:
Shortness of breath
Fever greater than 101°F
Weight loss
Drenching sweats while you sleep
Coughing up blood or bloody sputum
Chronic cough in a smoker

What if I am not responding to the prescribed medications?
It’s important to recognize that respiratory problems are interrelated and may coexist. Patients with allergies, get sinusitis and both of these conditions are linked to asthma. Sinusitis and reflux coexist in many patients. If these conditions can be ruled out, then for the 10% of chronic cough patients who do not have asthma, allergy or reflux, other conditions should be considered. Some have a disorder of the larynx called paradoxical vocal fold motion, PVFM (aka-vocal cord disorder). Others have a problem of irritability of the larynx (the “Hypersensitive Larynx“). These conditions are probably related and reflect an aberrant response to a routine sensory stimulus.